import React from 'react';

class Hello extends React.Component {

    constructor(props) {
        super(props);
        this.state = {date: new Date()};
    }

    componentDidMount() {
        this.timerID = setInterval(
            () => {
                this.setState({
                    date: new Date()
                });
            },
            1000
        );
    }

    componentWillUnmount() {
    }

    render() {
        return (
            <div>
                <h1>Hello, world!</h1>
                <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
            </div>
        );
    }
}

export default Hello;
